Starting a simple WebSocket Server with Spring integration - spring

Question

I am trying to start a simple websocket server in a spring integration application.
I build my application thanks to the following dependancies :
dependencies {
compile("org.springframework.boot:spring-boot-starter-integration")
compile("org.springframework:spring-websocket")
compile("org.springframework.integration:spring-integration-ip")
compile("org.springframework.integration:spring-integration-websocket")
compile('com.fasterxml.jackson.core:jackson-databind')
compile("org.springframework.integration:spring-integration-feed")
}
I launch my application thanks to the following Java file :
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.annotation.Configuration;
org.springframework.integration.annotation.IntegrationComponentScan;
#Configuration
#EnableAutoConfiguration
#IntegrationComponentScan
public class Application {
public static void main(String[] args) throws Exception {
ConfigurableApplicationContext ctx = new SpringApplication("/integration.xml").run(args);
System.out.println("Hit Enter to terminate");
System.in.read();
ctx.close();
}
}
Here is my "integartion.xml" :
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:int="http://www.springframework.org/schema/integration"
xmlns:file="http://www.springframework.org/schema/integration/file"
xmlns:feed="http://www.springframework.org/schema/integration/feed"
xmlns:int-ip="http://www.springframework.org/schema/integration/ip"
xmlns:ws="http://www.springframework.org/schema/integration/websocket"
xsi:schemaLocation="http://www.springframework.org/schema/integration/feed http://www.springframework.org/schema/integration/feed/spring-integration-feed.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/integration/file http://www.springframework.org/schema/integration/file/spring-integration-file.xsd
http://www.springframework.org/schema/integration http://www.springframework.org/schema/integration/spring-integration.xsd
http://www.springframework.org/schema/integration/ip http://www.springframework.org/schema/integration/ip/spring-integration-ip.xsd
http://www.springframework.org/schema/integration/websocket http://www.springframework.org/schema/integration/websocket/spring-integration-websocket.xsd">
<int-ip:udp-inbound-channel-adapter id="udpReceiver"
channel="udpOutChannel"
port="11111"
receive-buffer-size="500"
multicast="true"
multicast-address="225.6.7.8"/>
<int:object-to-string-transformer input-channel="udpOutChannel" output-channel="stringified"/>
<bean id="nmeaParser" class="transformers.NMEAParser"/>
<int:transformer input-channel="stringified" ref="nmeaParser" output-channel="parsedData"/>
<int:channel id="jsondata"/>
<int:object-to-json-transformer input-channel="parsedData" output-channel="jsondata"/>
<ws:server-container id="server" path="/position"/>
<ws:outbound-channel-adapter container="server" channel="jsondata"/>
</beans>
As you can see, I create an UDP inbound channel. This channels works like a charm. I am able to see that data are sucessfully passed to my "NMEAParser" bean.
I think that my Websocket server doesn't work because :
I can't connect to it with wscat... When I try to do :
wscat -c ws://127.0.0.1:8080/position
I receive a "CONNECTION REFUSED", the same message I receive when nothing is launched.
In the Spring log's I can read this :
Starting beans in phase 0
Adding {object-to-string-transformer} as a subscriber to the 'udpOutChannel' channel
Channel 'application:8080.udpOutChannel' has 1 subscriber(s).
started org.springframework.integration.config.ConsumerEndpointFactoryBean#0
Adding {transformer} as a subscriber to the 'stringified' channel
Channel 'application:8080.stringified' has 1 subscriber(s).
started org.springframework.integration.config.ConsumerEndpointFactoryBean#1
Adding {object-to-json-transformer} as a subscriber to the 'parsedData' channel
Channel 'application:8080.parsedData' has 1 subscriber(s).
started org.springframework.integration.config.ConsumerEndpointFactoryBean#2
Adding {websocket:outbound-channel-adapter} as a subscriber to the 'jsondata' channel
Channel 'application:8080.jsondata' has 1 subscriber(s).
started org.springframework.integration.config.ConsumerEndpointFactoryBean#3
Adding {logging-channel-adapter:_org.springframework.integration.errorLogger} as a subscriber to the 'errorChannel' channel
Channel 'application:8080.errorChannel' has 1 subscriber(s).
started _org.springframework.integration.errorLogger
Starting beans in phase 1073741823
started udpReceiver
Started Application in 0.792 seconds (JVM running for 1.121)
We can see here that all my beans are launched, except the bean "server" which is my server container. There is no trace of this bean in this log message.
To write my application I read carrefully this sampe and this doc.
What am I doing wrong, or what I forgot ?

Answer 1

As discussed in the chat after our lengthy comment back and forth, you need org.springframework.boot:spring-boot-starter-websocket in your dependencies, this will bring in spring-boot-starter-web and org.springframework.boot:spring-boot-starter-tomcat transitively, giving you a websocket runtime.